Avoidance of subaortic obstruction in staged management of single ventricle

Background: Subaortic obstruction is a frequent accompaniment of single-ventricle anatomy. Most often, the aorta arises from an outflow chamber that is connected to the single ventricle by a bulboventricular foramen or ventricular septal defect. This connection may be restrictive of flow at birth, or may become obstructive after surgical procedures that reduce the volume work of the ventricle. Subaortic obstruction is recognized as a risk factor for reconstructive surgical procedures for single ventricle. Methods: To prevent the consequences of subaortic obstruction, we have routinely amalgamated the proximal main pulmonary artery with the ascending aorta and arch early in the management of these patients. From September 1990 through September 1994, 29 neonates and infants with single ventricle and established or potential subaortic obstruction underwent staged reconstructive surgical procedures. The initial operation in the newborn period was a Norwood procedure (18 patients) or a pulmonary artery band (5 patients). All survivors underwent a hemi-Fontan procedure at approximately 6 months. Results: Eighteen patients have undergone a completion Fontan operation with no deaths. Five await completion Fontan. None has subaortic obstruction, and none has pulmonary valve insufficiency that is graded more than mild. Conclusions: Early association of the proximal main pulmonary artery with the ascending aorta appears to obviate the risks and complications associated with subaortic obstruction in patients with single ventricle.